Sigma rule: Potential SSH Tunnel Persistence Install Using A Scheduled Task

Rule

Title

Potential SSH Tunnel Persistence Install Using A Scheduled Task

Status

experimental

Level

high

Author

Rory Duncan

Date

2025-07-14

File

rules/windows/process_creation/proc_creation_win_schtasks_openssh_tunnelling.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the creation of new scheduled tasks via commandline, using Schtasks.exe. This rule detects tasks creating that call OpenSSH, which may indicate the creation of reverse SSH tunnel to the attacker's server.

Log source

product

windows

category

process_creation

Detection

selection_img:
    - Image|endswith: '\schtasks.exe'
    - OriginalFileName: 'schtasks.exe'
selection_cli_sshd:
    CommandLine|contains|all:
        - ' /create '
        - 'sshd.exe'
        - '-f'
selection_cli_ssh:
    CommandLine|contains|all:
        - ' /create '
        - 'ssh.exe'
        - '-i'
condition: selection_img and 1 of selection_cli_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.privilege-escalation
• attack.persistence
• attack.execution
• attack.t1053.005
• attack.command-and-control

MITRE ATT&CK ids this rule names

• T1053.005

References

• https://thedfirreport.com/2023/10/30/netsupport-intrusion-results-in-domain-compromise/
• https://www.kroll.com/en/insights/publications/cyber/cactus-ransomware-prickly-new-variant-evades-detection

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_schtasks_openssh_tunnelling.yml